Stable and non-hygroscopic silica gel supported aluminium chloride（SiO_2-AlCl_3）,which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous cat...Stable and non-hygroscopic silica gel supported aluminium chloride（SiO_2-AlCl_3）,which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous catalyst for the condensation of indole with aldehydes and ketones to afford bis-indolylmethanes at room temperature under solvent-free conditions.The catalyst can be reused up to five times after simple washing with ether.展开更多
This study presents the fabrication and temperature sensing properties of sensors based on aluminium phthalocyanine chloride （AlPcCl） thin films. To fabricate the sensors, 50-nm-thick electrodes with 50-μ gaps betw...This study presents the fabrication and temperature sensing properties of sensors based on aluminium phthalocyanine chloride （AlPcCl） thin films. To fabricate the sensors, 50-nm-thick electrodes with 50-μ gaps between them are deposited on glass substrates. AlPcCl thin films with thickness of 50–100 nm are deposited in the gap between electrodes by thermal evaporation. The resistance of the sensors decreases with increasing thickness and the annealing at 100 ℃ results in an increase in the initial resistance of sensors up to 24%. The sensing mechanism is based on the change in resistance with temperature. For temperature varying from 25 ℃ to 80 ℃, the change in resistance is up to 60%. Simulation is carried out and results obtained coincide with experimental data with an error of ±1%.展开更多
Porous Al structures have been made using a porogen leaching method but with additional novel steps. In this way, Al-0.25Cu-0.6Si-1.0Mg alloys with interconnected, open cells have been made, with high levels of poros...Porous Al structures have been made using a porogen leaching method but with additional novel steps. In this way, Al-0.25Cu-0.6Si-1.0Mg alloys with interconnected, open cells have been made, with high levels of porosity（up to 89%）. The use of 4 to 5 mm diameter sodium chloride droplets combined with interspersion of the metal powder and droplets in the die and dissolution of the salt before sintering was found to enable easier interspersion of the two components, resulting in good connectivity of the beads via the formation of ‘‘windows＇ ＇ between the pores, and rapid elimination of salt from the structure. Porous Al with densities in the range of 0.28–0.86 g/cm3 exhibited compressive yield strengths in the range of 0.14 to 7.5 MPa, with no difference being observed between the samples made by this route and by more conventional dissolution of the salt after sintering. These novel steps widen the possibility for porous metal manufacture to other materials, not limited by the need to have a sintering temperature below that for the melting point of salt.展开更多
基金the partial support of this study by the Shahrekord University and the Islamic Azad University,Shahr-e-Rey branch Research Council
文摘Stable and non-hygroscopic silica gel supported aluminium chloride（SiO_2-AlCl_3）,which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous catalyst for the condensation of indole with aldehydes and ketones to afford bis-indolylmethanes at room temperature under solvent-free conditions.The catalyst can be reused up to five times after simple washing with ether.
基金Project supported by the Center of Excellence for Advanced Materials Research(CEAMR)King Abdulaziz University,Jeddah(Grant No.CEAMR-434-03)
文摘This study presents the fabrication and temperature sensing properties of sensors based on aluminium phthalocyanine chloride （AlPcCl） thin films. To fabricate the sensors, 50-nm-thick electrodes with 50-μ gaps between them are deposited on glass substrates. AlPcCl thin films with thickness of 50–100 nm are deposited in the gap between electrodes by thermal evaporation. The resistance of the sensors decreases with increasing thickness and the annealing at 100 ℃ results in an increase in the initial resistance of sensors up to 24%. The sensing mechanism is based on the change in resistance with temperature. For temperature varying from 25 ℃ to 80 ℃, the change in resistance is up to 60%. Simulation is carried out and results obtained coincide with experimental data with an error of ±1%.
基金Romanian National Centre for Studies in Scholarships Abroad (H.G. nr. 697/1996) for financial support
文摘Porous Al structures have been made using a porogen leaching method but with additional novel steps. In this way, Al-0.25Cu-0.6Si-1.0Mg alloys with interconnected, open cells have been made, with high levels of porosity（up to 89%）. The use of 4 to 5 mm diameter sodium chloride droplets combined with interspersion of the metal powder and droplets in the die and dissolution of the salt before sintering was found to enable easier interspersion of the two components, resulting in good connectivity of the beads via the formation of ‘‘windows＇ ＇ between the pores, and rapid elimination of salt from the structure. Porous Al with densities in the range of 0.28–0.86 g/cm3 exhibited compressive yield strengths in the range of 0.14 to 7.5 MPa, with no difference being observed between the samples made by this route and by more conventional dissolution of the salt after sintering. These novel steps widen the possibility for porous metal manufacture to other materials, not limited by the need to have a sintering temperature below that for the melting point of salt.
